OK so every winter when it cools down a bit and I drive my truck for a while then stop for 15 min. It won't start or will have trouble. It will just keep cranking unless I can feather life into it. It seems to be getting flooded. Replaced crank shaft position sensor and it helped a little. What else?

 

3.4 motor. T100

 

Is your MIL on?? Have you pulled the codes??

Define your winter?

To some temps in the 50`s are the cold of winter others might see 50below zero F

The winter blend gas most times makes starting easier.

When was the last set of wires and spark plugs fuel filter ??

 

It happens in cold weather, for me its 32-60 usually not below 50 degrees or so. I think its when my truck is between cold and at running temperature. So after 15 minutes of sitting in cold weather. Have not replaced fuel pump or spark plugs/wires for a good 10 years at least.

Im thinking it has to be a sensor with something to do with air fuel mixture.

I have a lean code showing but that happens on and off for years. This starting issue started last year.

The lean code could be part of the problem i guess. Could that make the engine flood and not start combined with a sensor or something?

Ive had my mechanic take a look, they hook it up to the computer, while its turning over and not starting the computer says everything is fine..

 

So in other words you have a fail to start problem and your mechanic sees no problem.

How does it start after sitting long periods like 8 hours plus.

If it was a sensor the OBD II system is quite good at letting you know

Also a real time scan with the vehicle running should show any issues.

Could be as simple as a loose ground condition or your ECM is on the way out.

Could be the fuel filter ?

perhaps just lack of maintenance !!

If your mechanic can`t find the problem time to find one that can

If you clear the codes will it start up at that point??

 

It starts great sitting for 8 hours, 500 hours, even 1 hour, It just has the problem when its sitting for 15-30 minutes or so. They ran a real time scan while the truck was having the fail to start problem.

Fuel filter was replaced somewhat recently, I keep up the maintenance pretty well, Plugs and fuel pump are due soon I think... but so far those are not the problem.

The codes dont make a difference, The shop kept it for a week and drove it, let it sit, reproduced the starting problem, Still no luck.

Im convinced it has something to do with the temperature, One of the mechanics mentioned something about two sensors in two different places cool down at different rates so it screws with the fuel mixture... But I dunno...

 

Sounds like you need to find a shop that knows what they are doing.

Have the truck for a week and have the issue occur and can`t fix it??

All the sensors can be watched on a real time scan well with my set up any how.

If it is showing a code it is easy to follow Toyota`s diagnostics step by step to find your problem

Very well could be the T100 curse it was a learning curve like New Coke!!

In any case Good Luck

 

Test coils when cold, then test them again when hot. Could also be something expanding causing a vacuum leak when warm, but shrinks up and seals well enough to start when cold.

 

I suspect the VSV line to the fuel pressure regulator.

 

I got the coolant temperature control unit/module replaced. Didnt fix it.

Ill have to look in to the VSV line.

I guess it could be the coils? but why would temperature effect them?

Its fine hot or cold. just in between. Maybe two different materials cooling down at different rates causing a leak i guess?


thanks for your input guys.